1. Field of the Invention
The present invention relates to a battery mounting structure for a small watercraft. More particularly, the present invention relates to a battery mounting structure for a small watercraft which provides for waterproofing protection and improves the turning characteristics of the small watercraft.
2. Description of the Background Art
A personal watercraft is known as a small size craft that is constructed and arranged to glide on the surface of a sea or lake. Many jet skis and other different types of personal watercraft are known and are commercially available.
In the background art, one example of a known type of battery mounting structure for a small watercraft is described in JP-A-10-194195. FIGS. 6(a) and 6(b) of the present application are reproduced from the disclosure of JP-A-10-194195, and are included herein for discussion of the previously known battery mounting structures.
In the above reference, as shown in FIGS. 6(a) and 6(b), a vessel body 1 includes a hull 1a, which constitutes a lower portion thereof, and a deck 1b for covering on top of the hull. The watercraft of FIGS. 6(a) and 6(b) is includes an engine inside of the vessel body, and is constructed in such a manner that a jet propeller 5 is driven by a drive shaft 3 extending rearward from an engine 2 disposed in the vessel body 1. Exhaust from the engine is expelled via an exhaust pipe 7.
The drive shaft 3 is supported by a drive shaft supporting box 6 at the midsection thereof, and batteries 4a, 4b are disposed separately on the right side and the left side of the vessel body 1 as shown in FIG. 6(b).
Small watercrafts of the type described in the above-cited reference are commonly used for sport racing as well as recreational purposes. In the case of sport racing, turning performance of the watercraft is a critical attribute and is a highly desirable. The ability to turn the watercraft within a tight and small turning radius is desirable for optimal performance. During operation of the small watercraft, the vessel can overturn in the water, resulting in at least a small amount of water entering the vessel.
In the battery structure in the background art as described above, the heavy batteries 4a, 4b are spaced a significant distance apart, as shown, and are disposed separately on the left and the right sides of the vessel body 1. With the weight distribution provided by the battery placement shown in FIG. 6(a), it is difficult to strike a weight balance and to centralize a mass (to place heavy parts at the center of the vessel as much as possible), and thus it is difficult to improve turning performance.
In addition, there is such problem that when restoring the vessel body 1 to a normal posture after having rolled over in the water, one of the batteries 4a, 4b disposed separately on the left and the right sides of the vessel body 1 comes in contact with water remaining in the vessel. Therefore, it is necessary to waterproof the batteries 4a, 4b very well, to prevent electrical problems and to insure that the operator is not stranded in open water in a “no start” condition.
Although the known devices have some utility for their intended purposes, a need still exists in the art for an improved battery mounting structure for a personal watercraft. In particular, there is a need for an improved battery mounting structure for a small watercraft, in which the battery mounting structure provides waterproofing protection for a battery stored therein, and improves the turning characteristics of the small watercraft.